There are many devices that make the daily life of a modern human being comfortable. For example, there are a tap water supply device supplying clean water conveniently, a gas supply device providing a heating power for cooking at an economical price, and an electricity supply device providing power for lighting and diverse electric devices. These devices are necessarily set up in the living space of a modern person. When a building is a residential space, the building is equipped with all the devices. Even though the building is not a residential space, such as offices and lecture rooms, the electricity supply device is essential.
While these devices make the life of a human being convenient, when there is a breakdown or malfunction, a disastrous accident may occur. In particular, when a breakdown or malfunction occurs and there is no person in a corresponding space and thus the breakdown or malfunction is kept for a long time, the possibility for such a disaster becomes even higher. For example, when a person goes out for a long time with a gas pipe valve open or a gas range switched on without knowing gas leakage, gas leaks out and stays in the interior. Accordingly, when a person enters the space, the person may inhale the gas and fall sick. When there is an inflammable, it may lead to an explosive fire accident.
Other than such a disastrous accident, waste of energy caused by the leakage of electricity and tap water rises as a serious problem as well. Especially, offices, lecture rooms, and public buildings consume a great deal of power because they not only require high illumination but also keep lights turned on and on due to many people going in and out frequently. To take one example, the last person leaving a lecture room after a lecture is over is supposed to turn the lights off. However, it may be obscure who the last person is and according to behavioristic psychology, it is widely known that when a duty is scattered to many people, the possibility that a person completes the duty is decreased drastically. Therefore, lights in a space where many people use are not likely to be turned off properly. Although there is no need to keep lights turned on when there is no person in the space, lights are turned on and on and this wastes a great deal of electricity. Also, because the lights are kept to be turned on for a long time, electric facility may be damaged due to overheat and furniture or interior articles in the space may be deteriorated. This may be another problem.
In other to resolve these problems, apparatuses for automatically cutting off resources in a resources supply device such as a tap water supply device, a gas supply device, and an electricity supply device when no person is sensed in the interior of a space have been disclosed. Conventional apparatuses, however, are designed to count the number of people in a space with a counter. Thus, there is a possibility of malfunction such as sensing and counting a crowd of people simultaneously going in and out of the space as one person. Therefore, the conventional apparatuses cannot effectively sense whether there is anyone in the space or not. The conventional apparatuses should count the number of people going in and out of the space and have a logic in consideration of diverse unexpected and exceptional circumstances. For example, when a huge load is being carried and a patent or an old man is going in and out, it takes a far longer time than an average time for passage and the apparatuses should be equipped with complicated devices and logics to take them into consideration. With simple devices and logics, the possibility that conventional apparatuses may malfunction becomes high.